Ten years ago, a tiny web site asked people to volunteer to write their own encyclopedia. Today, Wikipedia is the most widely used reference work in the world. Rapid advances in digital media and technology are changing how we connect to information and each other. The way we engage in public dialogue, coordinate, solve problems—all of it is shifting. New networks are emerging everywhere. It’s exciting—and frightening. What is this new network-centric world? What does it mean for community change?